Saturday, May 31, 2014

Bike wrecked and fixed

This past Tuesday I had a two-stage accident with my road bike that left me with a bit of road rash, and the bike a lot worse off. The derailleur got ripped off the frame and destroyed, the derailleur hanger was twisted and broken, a bunch of spokes got mangled and the chain got twisted.  The left brake hood is scraped up and the bar was twisted to the left but that's not anything to worry about.

Today (Saturday) the parts I needed (rear derailleur and spokes) arrived.  Combined with the derailleur hanger and new tire that I already had on hand, the rear wheel is rebuilt and the derailleur is mounted, adjusted and shifting again.  I actually just unbent the chain.  It seems like it's doing OK.  If it causes me any trouble I have a new chain to put on it too.

Monday, May 26, 2014

Classic handheld gaming

My neighbor had an old original Gameboy sitting around and gave it to my son.  It had corroded old batteries in it.  Even after removing them and plugging in the power supply, it just continually rebooted.

Playing Super Mario after repairing the machine.

We cracked it open and discovered that a chip near the cartridge connector had corrosion completely covering the pins on one side, and a little corrosion on the other.  The photo below is after a certain degree of circuit cleaner spray, toothbrush and toothpick work.

The eventual solution was to put it under the USB microscope at highest magnification and clean with an X-Acto hobby knife.  This revealed that one of the pins had come completely loose from the circuit board due to the corrosion.  Flux was applied with a flux pen, and the contacts re-soldered.  We now have a working Gameboy, with Super Mario and Tetris carts!

Sunday, May 25, 2014

Countdown to Duckon

I'm finishing up the last few things I need to get ready before I head out to run the Blinkies room at Duckon. Today I wrote a few more patterns for the free blinkie and programmed all 100 chips.  The kits are all packaged already, and the assembly instructions are written complete with very good photos thanks to the new USB microscope that I bought.  I still need to print out a couple dozen of each instructions, and I need to build some blinkies for GoH gifts.

Actually I programmed them twice because I forgot to set the default startup pattern to "rotate all patterns" the first time.

Luckily I have a new programmer, the MiniPro TL-866.  It is pretty fast, though I'm only programming 4K into flash so it doesn't make that much difference.

I was thinking as I was using this, pretty much all of the pins on this programmer can be set to do anything, so it's likely that with the right software, you could load 4 or 5 chips into it and program them all at once, or at least sequentially.  Then I saw the "multi program" button.  But no joy, apparently that's just to use multiple MiniPros at once.

I will probably not burn the chips for the big blinkie until next weekend.  I did write a few new patterns for it yesterday, but I'd like to put in more.  I'm just running out of ideas.

Wednesday, May 14, 2014

Nozzle cleaning the right way

Go to this page: by Whosa-Whatsit - nozzle clearing by cold-pull, especially with nylon filament.  Very impressive results.  I've been able to do cold pulls with a JHead hotend very easily even with PLA.  I was never able to do a cold pull at all with a Makergear hotend (the ones from 2-3 years ago).

Thoughts on inverter and generator sales pitches

So, when you're shopping for inverters or generators, they make a big deal about the power being "clean sine wave" because "then you can power sensitive electronics like computers"

I think these days (IE last 5 to 10 years) that's exactly opposite of true.  Computers and really any electronics are pretty much required to be energy star compliant, which means they're all running off switching supplies, and most of them are universal, usually 85 to 250 volts.  The very first thing that a switching supply does is rectify the inbound power to pulsating DC - it would actually run BETTER off a square wave than off a sine wave.

So you could run most modern electronics off the nastiest-ass power, varying wildly from 100 to 200 volts, frequency all over the shop, square wave, triangle wave, sine wave, wavy wave, and it probably wouldn't give a toss about it and it would run just fine.

It's motorized appliances and power tools that would probably be most affected - using a non-sine wave will affect the efficiency and power output of a synchronous motor and probably would irritate even brushed motors.  It'd be really irritating to something like a refrigerator.